I am currently making progress with a brand new map named pl_crater, its almost finished and i will first release it as a unofficial alpha version and later, with help from my Alpha Testers, release a public beta version, currently you can do 2 things to help me 1: why it is not finished because i am facing problems, first the payload will not push, RED will always spawn on BLU and source only recognises the 1st checkpoint(FIXED) 2: you can join my alpha testing group at http://steamcommunity.com/groups/pl_crater
its good to see that youre going to so much effort to make sure you get enough testing, but TF2maps.net already has an excellent testing infrastructure in place. You dont need to bother with a testing group, you can join in the gamesdays and so on.
For your Payload cart troubles, it would take some work to replace your current setup, but you could try using the PL systems found in A Boojum Snark's Ultimate Mapping Resource Pack. With a little tweaking, they'll work in any map with very little fuss. And yes, bring your map over here in any playable state to have it tested.
Same as everything above, there is no need to create and organize your own testing. All you really need to do is put it in our gamedays (over here) and people will be happy to test your map. There is also a nifty feature on our servers where when people test your map, they can leave feedback inside it at the co-ordinates that a problem is at. The feedback can be seen here after your map has been tested. With your payload problem, download the ABS ultimate mapping resource pack (link above) and you can do practically any game type with much less effort than having to create your own entity system. Finally, what i probably should have said at the start, Welcome to the forums. Feel free to look around, ask questions, join us on steam chat and have fun mapping.
ACH NOOO! Been working on a map for a month or so now named PL_Crater. Guess you claimed the name first though. I gotta set up name claim threads in the future...